The makers of “Mr. Peabody & Sherman” were smart to realize one thing: If you’re going to make a feature length film based on the titular “Rocky and Bullwinkle” segment, you might as well make it a whole hog time travel movie. The shows were little history lessons, with the WABAC Machine the mere device to send the canine braniac and his quizzical adoptee back in time. The movie reverses this. It has very little educational value (same with the show, to be honest). It’s essentially “Bill and Ted’s Excellent Adventure,” only with more heart.

And therein lies the less smart thing about “Mr. Peabody & Sherman”: “Bill and Ted’s Excellent Adventure” already exists, and is much more joyous than anything here. Doing it again only with more life lessons is two unimaginative things rolled into one pricey franchise launcher. Here, boy Sherman (voice of Max Charles) takes the (of course) souped-up Wayback Machine for a joy ride, only to accumulate multiple historical personages. Eventually the film starts cribbing from other time travel pictures. Sherman winds up creating multiple time lines, and with them multiple Shermans.

But as soon as it seems “Mr. Peabody & Sherman” may get really loopy and turn into a kiddie “Primer,” it backs off. Director Rob Minkoff (“The Lion King,” “Stuart Little”) makes it looks handsome, but maybe too handsome. He doesn’t have the madcapness to fully exploit a potentially nutty premise. It has the entirety of history at its disposal, but it can’t give Agamemnon (Patrick Warburton), Mona Lisa (Lake Bell) or even Sigmund Freud (Mel Brooks!) anything to do.

Then again, it has other more serious concerns to get to. The world at large, it turns out, is sort of freaked that a child is being raised by a talking dog (Ty Burrell, doing a not bad approximation of original voice Bill Scott). The slight subversiveness of asking America to be more tolerant of (nudge nudge) alternative parenting, unfortunately, comes off as just another obligatory family movie homily.

On top of that, Peabody has to learn his own obligatory lesson about being emotionally available to the kid he’s raised as his own. If you ever thought that semi-sincere message-mongering has destroyed many a family picture, the wasted potential of “Mr. Peabody & Sherman” will make you want to build your own time machine and do it right before the sequels screw it up as well.